1. Field of the Invention
This invention relates to an electronic timepiece which can effect the compensation operation with respect to external shock so as to prevent its erroneous operation.
2. Description of the Prior Art
Many attempts have been made to drive a step motor by a small power output under no load or light load and by a large power output under a heavy load. In this case, the load mainly consists of a solid resistance load such as a wheel train, week date feeding mechanism or the like and of a fluid resistance load such as oil or the like. The above mentioned attempts can compensate for these loads, but are insufficient in compensation action with respect to the external shock load and hence have the drawback that, when a step motor is reversely rotated by 1 step due, for example, to the reversely rotating shock, the timepiece is delayed by 2 seconds. As a result, in order to prevent the step motor from rotating in a reverse direction, the drag torque between the permanent magnet rotor and the stator can not be made too large. As a result, the power input required to rotate the rotor by 1 step for the purpose of making the potential energy large becomes large. Thus, it is impossible to reduce the electric power required for the electronic timepiece to a value smaller than a certain limit.